1. Field of the Invention
Illustrative embodiments of the present invention relate to an image forming apparatus, such as a copier, a printer, or a facsimile, and more specifically, to an image forming apparatus including a cooling device to cool a heat generator and/or an imaging unit that is located near the heat generator.
2. Description of the Background
A conventional image forming apparatus includes a cooling device to cool a heat generator. The heat generator is usually provided in a fixing device or other such device. Sometimes the heat generator is provided at an imaging unit that is located near the heat generator.
Typically, the cooling device employs a fluid cooling method involving circulating a coolant. In the fluid cooling method, a heat-receiving section including a channel (hereinafter, a “heat-receiving-section channel”) through which a coolant flows is provided near the heat generator or the imaging unit. When the coolant absorbs heat from the heat generator or its neighboring portion at the heat-receiving section, the coolant having taken the heat is transported from the heat-receiving-section channel to a cooling section, where a radiator or the like of the cooling section radiates heat from the coolant to cool the coolant. Then, the coolant is transported back to the heat-receiving-section channel. Thus, the coolant is circulated between the heat-receiving section and the cooling section to cool the heat generator or the imaging unit.
Conventional image forming apparatuses are known that include a cooling device employing a fluid cooling method to cool a detachable process cartridge installed in the apparatus. These apparatuses may be configured so that the cooling device is provided at a main body, or the cooling device is provided at the main body while the heat-receiving section of the cooling device is integrated into the process cartridge.
In a conventional image forming apparatus, the fixing device may be detachable from the main body of the apparatus to allow paper jams to be cleared and servicing to be performed. During a fixing operation carried out by the fixing device, the temperature of the fixing device may rise up to a relatively high temperature (e.g., approximately 200° C.). Therefore, from the viewpoint of safety, it is desirable that a user or a service person draws the fixing device out of the main body for operation only after the fixing device is cooled by a cooling device. The problem here is that, in the above-described configuration in which the cooling device is provided at the main body, the fixing device is not cooled by the cooling device once it is removed from the main body.
Alternatively, for the above-described another configuration as well, in which the cooling section of the cooling device is provided at the main body while the heat-receiving section of the cooling device is integrally provided with the fixing device, the heat-receiving section is separated from the cooling section when the fixing device is detached from the main body. As a result, since the heat-receiving-section channel and the circulation path are separated, the fixing device is not cooled after being detached from the main body. Consequently, the temperature of the fixing device may be maintained relatively high during servicing operation, posing a danger when a user or a service man touches the fixing device.
Alternatively, it is conceivable that the cooling section is also integrally provided with the fixing device so that a coolant is circulated to cool the fixing device with the fixing device detached from the main body. However, such a configuration may increase the size of the fixing device, reducing the performance of clearing a paper jam due to the opening and closing of a cover of the fixing device. Further, such a configuration may require greater strength of the fixing device housing, a requirement that conflicts with market demand for more compact and lightweight designs.
Further, the above-described challenge is not limited to the fixing device and may also arise in a configuration in which any other device in the imaging unit, such as a developing device, which is located near the fixing device and whose temperature is raised by heat of the fixing device, is to be detachable from the main body.